In some embodiments, a layout-based electronic communication classification (e.g. spam filtering) method includes generating a layout vector characterizing a layout of a message, assigning the message to a selected cluster according to a hyperspace distance between the layout vector and a central vector...http://www.google.com.tw/patents/US8065379?utm_source=gb-gplus-share專利 US8065379 - Line-structure-based electronic communication filtering systems and methods
